Objective: The primary objective of this study was to identify brain regions associated with behavioral measures of dystonia in a specific subtype called writer’s cramp (WC) in which dystonic movements are triggered by hand writing.

Background: Dystonia is a disabling brain disorder with no clear understanding of how brain abnormalities associate with behavioral measures of the disease, hindering better clinical therapies. Although a few prior neuroimaging studies identified relationships between brain abnormalities and clinical features of dystonia, there remain significant uncertainties about the relationship between brain abnormalities and behavioral manifestations of dystonia.

Method: Functional MRI were acquired from 20 WC and 22 healthy volunteers (HV) while subjects performed a writing task. Data-driven group independent component analysis was used to derive functional networks. To analyze brain-behavior relationships, functional network connectivity values were then correlated with peak accelerations, a sensitive and reliable measure of writing dysfluency in WC dystonia. Bootstrapping was used to analyze which dysfluency associated network connections showed group differences. These dysfluency-associated networks were then analyzed to identify which brain regions within each network contributed to group differences.

Results: Of the 16 networks generated, worsening writing dysfluency was associated with decreased cortico-basal ganglia connectivity, decreased cortico-cortical connectivity and increased default mode-salient connectivity. Of these four functional network connections, WC showed significantly decreased cortico-basal ganglia connectivity compared to HV. Subregion analysis of cortical and basal ganglia networks showed that decreased connectivity in WC was largely due to decreased BOLD activity in left putamen, left thalamus and bilateral pallidum.

Conclusion: The present study suggests that to improve behavior in WC dystonia, rationally designed brain stimulation therapies should target network-level brain abnormalities, particularly in subcortical brain regions of left putamen, left thalamus, and bilateral pallidum.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/writing-dysfluency-associates-with-basal-ganglia-network-dysfunction-in-writers-cramp-dystonia/